KR20180054775A - Method and system for providing security against initial contact establishment of mobile devices and devices - Google Patents

Abstract

The present invention relates to a method of providing security for establishing an initial contact between a mobile device 12 and a device 14 wherein the device 14 is provided with a symmetric key 48 introduced via a trusted entity 16 / RTI > Introducing the symmetric key (48) to the mobile device (12) via the trusted entity (16); Performing a key exchange method (49) upon establishing contact with a result of the shared key (56) in the mobile device (12) and the device (14); Generating a first signature (60a) from the mobile device (12) via the shared key (56) to the symmetric key (48); Generating a second signature (60b) from the device (14) via the shared key (56) to the symmetric key (48); Transmitting the first signature (60a) to the device (14) and the second signature (60b) to the mobile device (12); Authenticating the device (14) by encrypting the second signature (60b) at the mobile device (12) with the symmetric key (48); Authenticating the mobile device (12) by encrypting the first signature (60a) at the device (14) with the symmetric key (48); And continuing the contact establishment at mutually successful authentication (164) or aborting (166) the establishment of the contact if at least one authentication fails. It is an object of the present invention to improve initial access to a device by a mobile device.

Description

Method and system for providing security against initial contact establishment of mobile devices and devices

The present invention relates to a method and system for providing security for establishing initial contact of a mobile device and a device.

Without directly accessing the vehicle and without preparing the vehicle for a new participant in advance, for example, via the Internet, the mobile device can be coupled to another device, such as a vehicle, via WLAN or Bluetooth (LE, low energy) .

Bluetooth provides a variety of pairing mechanisms, but they are not secure unless they include a so-called out-of-band acknowledgment that a person uses the channel to authenticate the connection. Without such a channel, man-in-the-middle attacks are possible, so it is not safe for the car or mobile device to establish a connection with whom or what. The same applies to WLAN connections. Without access to the vehicle and no possibility of displaying codes or PINs, out-of-band verification is impossible.

This situation occurs, for example, in a car sharing system. Known car sharing systems do not integrate with real vehicle systems, such as car anti-theft devices, and solve problems with upgrade solutions, which is costly.

DE 10 2009 042 141 A1 discloses a system having a wireless communication device, a vehicle and a server providing a key. This requires both the communication device and the vehicle to be connected to the server.

DE 10 201 23 225 742 A1 discloses a method for determining if a user of an electronic device is an authorized user of a vehicle. To this end, it is determined at the central server whether the user can perform the vehicle operation. If this is the case, the user is allowed to perform additional requests for the vehicle.

US 2010/0111307 A1 initiates in-band signaling in the optical transmission network to determine and control the session key.

DE 198 11 833 A1 discloses a combination of a Diffie-Hellman method and a public key encryption method and an end-to-end authentication, not a combination of a signature protocol and a classic Diffie- Initiate a key exchange protocol using a protocol

The present invention is now based on the task of improving initial access to the device by the mobile device.

The above object is achieved by the method according to claim 1 or the system according to claim 8.

A method based on symmetric keys in mobile devices and devices is presented.

In a method according to the present invention for providing security for establishing an initial contact between a mobile device and a device, the device is provided with a symmetric key introduced via a trusted entity,

Introducing a symmetric key to the mobile device via the trusted entity;

Performing a key exchange method upon establishing contact with the result of the shared key to the mobile device and the device;

- generating a first signature with a symmetric key over the shared key at the mobile device;

- generating a second signature with a symmetric key over the shared key at the device;

Transmitting a first signature to the device and a second signature to the mobile device;

Authenticating the device by encrypting the second signature with a symmetric key at the mobile device;

Authenticating the mobile device by encrypting the first signature with a symmetric key in the device; And

- continuing contact establishment upon mutual successful authentication, or aborting contact establishment if at least one authentication fails.

The method according to the present invention has the advantage that the device, for example another participating device or mobile device which has not previously been coupled to the vehicle, can also be authenticated as a key for secure use without access to the second device. Thus, any device, such as, for example, a smart phone, can now be used as a digital key of a device such as a vehicle. Thus, the method according to the invention is particularly suitable for car sharing. Another advantage is that the structure of the method can exclude man-in-the-middle attacks, thereby improving security. Also, since the necessary encryption material is already present in the vehicle, it is advantageous that the device need not be connected to a central server or the Internet. Only connection to the mobile device is needed. The method according to the invention provides a cryptographically secure connection of the coupling system of the transmission technology with an additional authentication mechanism. The device or vehicle's cryptographic material associated with the proposed method replaces the PIN verification of the pairing method. Thus, access to a device or vehicle, which is a common case for entering or confirming a PIN or key, is not required. Another advantage is that it can be augmented without the need to change existing pre-established methods already present.

The trusted entity may be, for example, a security server of a service provider, such as a vehicle manufacturer or a car sharing service. The trusted entity may be part of a public key infrastructure (PKI), for example an authentication entity. The step of introducing the key to the mobile device may be performed after the key exchange method is performed. As a key exchange method, a common method such as Diffie-Hellman can be used.

It is assumed that the transmission technique has a secure key exchange method (SAV), but the key exchange method is not secure for meson attack such as Diffie-Hellman. In general, the key exchange method is defined by an external material, such as, for example, a Bluetooth pairing method. Thus, the method according to the present invention uses or extends a preset key exchange method.

In other words, another method according to the present invention can proceed as follows. The key exchange method is carried out during the initial contact for coupling. For this purpose, a public key is used, and a shared key for the next communication exists. To authenticate these keys on both sides, i.e., to verify that the authenticated vehicle and the authenticated vehicle actually performed the key exchange method directly with each other, this unique feature of the key exchange method implementation is signed by both participants It is authenticated by other participants. Up to now, this step is done, for example, by checking the checksum of the user displayed on both devices.

For this purpose, for example, a digital fingerprint is performed using a feature of a strong encryption one-time function. This is characterized in that the prototype can not be deduced from the image of the function, i. E. From the digital fingerprint, and the image is always kept the same at the same input. The fingerprint should now be signed by both participants. The signature is performed based on the asymmetric key to which the following applies: The device is part of the trust chain of the public key infrastructure (PKI), and since the keys and certificates required for this are already introduced in production, And authenticates itself. The mobile device has previously obtained a certificate for authentication of the device via its interface to the device manufacturer's trust infrastructure (PKI) and a certificate of its own key for self-certification for the device. Each receiver can now authenticate the other participants by the fingerprint's transmitted signature being cipher-verified and the certificate of the transmitted key being cipher-verified, whereby the trust chain is each authenticated and manufactured. The participants can then securely and confidently communicate with each other based on the computed shared key.

In a method of providing security for establishing an initial contact between a mobile device and a device, the device is provided with a signed public device key and a corresponding private device key and a public key of the authentication entity, the method comprising the steps of:

Introducing the signed public mobile device key and the corresponding private mobile device key and the public key of the authentication entity to the mobile device;

Performing a key exchange method upon establishing contact with a result of a shared key in a mobile device and an apparatus;

- generating a first signature with the private mobile device key via the shared key at the mobile device;

- generating a second signature with the private device key via the shared key at the device;

- transmitting a first signature and a signed public mobile device key to the device and a second signature and signed public device key to the mobile device;

Authenticating the device by encrypting the second signature with the signed public device key and the public key of the authentication entity at the mobile device;

Authenticating the mobile device by encrypting the first signature with the signed public mobile device key and the public key of the authentication entity in the device; And

- continuing establishing the contact upon mutual successful authentication or stopping the establishment of contact if at least one authentication fails.

The same advantages and modifications as described above apply. The step of introducing the signed public mobile device key and the corresponding private mobile device key may be such that actual creation of such a key is made at the mobile device and the public mobile device key is sent to the authentication entity or backend, Lt; RTI ID = 0.0 > mobile < / RTI > device key is introduced into the mobile device.

Unlike the above method of using symmetric keys in mobile devices and devices, this method is based on asymmetric keys. Depending on the existing or desired public key infrastructure (PKI), one or the other method may be used.

It may be provided that the device itself generates and authenticates the signed public device key and the corresponding private device key, and that the necessary keys and certificates are introduced during device production. This assumes that the authentication entity is present in the vehicle, which can be simplified and more securely configured, especially by reducing the transmission of encryption material. Alternatively, the cryptographic material is preferably introduced into the vehicle at the time of production of the device within the scope of the public key infrastructure (PKI).

It may also be provided that the signed public key and the corresponding private key and the public key or symmetric key of the authentication entity are introduced into the device upon production of the device. This improves security because the production of the device occurs in a secure environment.

It may also be provided that the symmetric key or the signed public mobile device key and the corresponding private mobile device key and the public key of the authentication entity are introduced into the mobile device prior to contact establishment. This type of introduction allows complete preparation of a method that can be implemented without connecting to a server or a public key infrastructure (PKI) entity.

The key can be introduced by installing the program on the mobile device. For example, this introduction of the app form can be carried out simply and safely, and may also be accommodated by a potential user of the device.

The key exchange method can be based on the Diffie-Hellman method. For example, a coupling process or a pairing process may be performed by an elliptic curve Diffie-Hellman key agreement protocol in the "Secure Simple Pairing-New Merit Comparison" pairing mode. This approach requires only obvious hardware costs.

By exchanging the signature, verification can be made in the key exchange method. Thus, verification of the code generally required in the key exchange method can be replaced by exchange of the signature. In a typical pairing method, a code such as a PIN or a Long Term Key (LTK) must be identified and compared, but this is handled by a method that is automated and performed. This improves safety by eliminating malfunctions and improves convenience.

It may also be provided that other systems needed to perform the method are activated in the device only after successful mutual authentication. In this way, for example, a power supply such as a battery of a vehicle is prevented from being discharged, thereby preventing an unstable state of the apparatus.

A system in accordance with the present invention that provides security for establishing initial contact between a mobile device and a device provides that the mobile device and the device are installed in the manner described above. The same advantages and modifications as described above apply.

The device may be a vehicle and / or the mobile device may be a smart phone. This is a combination often encountered, for example, for car sharing services that can benefit from the system.

The mobile device and the device may each be provided with a transmitting / receiving unit for shared communication according to the Bluetooth low energy standard. These standards extend to devices such as mobile devices and vehicles, allowing for simple implementation.

The apparatus includes a transmitting / receiving unit installed to perform the above-described method and a computer unit connected thereto, and it is possible that another system of the apparatus can be activated through a control command of the computer unit only after authentication is performed have. The connected computer unit may be, for example, a communication control device of a vehicle. Advantageously, the targeted discharge of the vehicle battery can be prevented.

Further preferred developments of the invention will become apparent from the remaining features mentioned in the dependent claims.

The various embodiments of the invention referred to herein may advantageously be combined with one another, unless otherwise indicated in the individual case.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in the following with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a schematic diagram of a system for providing security for establishing initial contact between a mobile device and a device.
Figure 2 shows a schematic diagram of security provision for establishing initial contact of a mobile device and a device.
3 shows another schematic diagram of security provision for establishing initial contact of a mobile device and a device.

1 illustrates an embodiment of a system 10 that provides security for establishing an initial contact of a device such as mobile device 12 and vehicle 14. [ Here, an example of the vehicle manufacturer is selected for the system 10. The backend 16 of the vehicle manufacturer has an authentication entity 18 and a data bank 20 disposed therein. The backend 16, authentication entity 18 and data bank 20 are shown as dedicated units. In the data bank 20, it may be provided that other information such as the used cipher material is assigned to the vehicle 14. [

For example, it is possible to integrate all elements or multiple elements into a server. The authentication entity 18 may be implemented in whole or in part as software. The authentication entity 18 belongs to a public key infrastructure (PKI). The public key infrastructure includes the backend 16 of the vehicle manufacturer and the vehicle 14 of the manufacturer, one of which is shown by way of example.

The mobile device 12 may be, for example, a laptop or tablet or a mobile computer such as a smart phone, smart watch, data glasses or other wearable computer. The vehicle 14 may be, for example, a passenger car, truck, bus or motorcycle or railway vehicle, ship or aircraft.

The backend 16 has a first interface 24 for communicating with the vehicle 14 and a second interface 22 for communicating with the mobile device 12. The backend 16 or authentication entity 18 communicates with the vehicle 14 via the first interface 22. This is implemented via a connection 26, such as a WLAN or mobile wireless network or cable or Ethernet, for example. Preferably, during the production of the vehicle 14 in the safe environment of the vehicle manufacturer a connection 26 (26) is provided during the production of the vehicle 14, since such a connection 26 introduces a secret material, such as a symmetric key or a private key, Is activated. To this end, the vehicle 14 has a corresponding compatible interface 28.

The backend 16 or authentication entity 18 communicates with the mobile device 12 via the second interface 24. This is implemented, for example, over a connection 30 such as a WLAN or mobile wireless network or cable or Ethernet. Typically, such a connection 30 is publicly accessible, such as a mobile wireless network. To this end, the mobile device 12 includes a corresponding compatible interface 32.

In vehicle 14, a plurality of control devices 34 or other computing devices are located on one or more bus systems 36, for example in accordance with CAN standards. The vehicle also includes a transmit / receive unit 38 and a control unit 40 associated therewith. The transmit / receive unit 38 preferably operates wirelessly, for example, in accordance with Bluetooth LE (low energy) or WLAN standards. The control device 40 is installed to perform a so-called pairing method for establishing a connection with an external device such as the mobile device 12 via the transmitting / receiving unit 38.

The mobile device 12 also includes a corresponding transmit / receive unit 42 that allows a connection 44 with the transmit / receive unit 38 of the vehicle 14 to be set. The microprocessor 46 of the mobile device 12 is configured to perform a pairing method to establish a connection with an external device, such as the vehicle 14, via the transmit / receive unit 42. Programs or apps downloaded from backend 16 may also be used.

Referring now to Fig. 2, a first embodiment of providing security for initial contact establishment of mobile device 12 and device 14 will be described. The device 14 may be, for example, the vehicle 14 or the control device 40 of Fig.

Prior to establishing an initial contact between the mobile device 12 and the device 14, the two participants are shared, i.e. have the same symmetric key 48, in the scope of the pre-provision. The symmetric key 48 is issued by a trusted entity, such as the manufacturer's backend 16. The device 14 obtains data for deriving the symmetric key 48 or the symmetric key 48 already in production, and the mobile device 12 is symmetric when it is playing software or registering a service such as a car sharing service. Key 48 is obtained.

Upon establishing contact between the mobile device 12 and the device 14, a key exchange method 49 is performed. As an example, a Diffie-Hellman method is shown. The mobile device 12 includes a private key 50a and a public key 52a and the device 14 includes a private key 50b and a public key 52b. Mobile device 12 and device 14 now exchange their public keys 52a and 52b.

In the key generation step 56, the mobile device 12 generates the shared key 56 from its private key 50a and from the public key 52b of the device 14. Similarly, the device 14 creates a shared key 56 from its private key 50b and from the public key 52a of the mobile device 12. Thus, the key exchange method 49 ends here.

Now, within the scope of the signature generation 58, a first signature 60a is generated from the mobile device 12 via the shared key 56 to the symmetric key 48. Similarly, within the scope of signature generation 58, a second signature 60b is generated from the device 14 via the shared key 56 to the symmetric key 48.

The first signature 60a is then sent to the device 14 and the second signature 60b is sent to the mobile device 12. [ This is done through the same interface or connection that causes the key exchange method 49 to be performed. This may be, for example, a connection 44 with the interface or transmit / receive units 38 and 42 of FIG.

In the scope of authentication 62, the device 14 is authenticated by encrypting the second signature 60b from the mobile device 12 to the symmetric key 48. Similarly, within the scope of authentication 62, mobile device 12 is authenticated by encrypting the first signature 60a from the device 14 to the symmetric key 48.

At successful authentication 64, i.e., upon mutual authentication, contact establishment continues. For example, in the example of FIG. 1, another system, such as the bus 36 of the device 14 and / or another control device 34, is then activated by a control command of the control device 40.

At the time of unsuccessful authentication 66, i.e., when at least one authentication 62 has failed, the establishment of contact in the device 14 or the mobile device 12 is stopped.

Next, a possible routine example is described. The car owner or car sharing service provider seeks to issue a digital vehicle key to the customer via the mobile terminal or mobile device. B's mobile device 12 is Bluetooth low energy or BT classic or WLAN capable. Through the backend system 16, the newly issued digital vehicle key is transferred to the mobile device 12 of B. In addition, symmetric or asymmetric key material is distributed to the mobile device 12.

B moves to the vehicle 14 with his mobile device 12 in the radio range, the coupling process is automatically initiated by the elliptic curve Diffie-Hellman key agreement protocol in the "Secure Simple Pairing - New Merit Comparison" pairing mode . The mobile device 12 and the vehicle 14 set a Long Term Key (LTK) here and then express it in a six-digit number through an agreed secret to prevent a man-in-the-middle attack It is expected to confirm the fingerprint. Both of these requested user interactions are ignored and automatically verified by the software. This authentication of the negotiated key material is ensured in a step subsequent to the standardized coupling method, via the key material already provided via distribution and subsequent verification. Thus, despite the lack of user interaction, mutual key authentication and therefore resistance against man-in-the-middle attacks is assured.

Referring now to FIG. 3, a second embodiment of security for initial contact establishment of mobile device 12 and device 14 will be described. The device 14 may be, for example, the vehicle 14 or the control device 40 of Fig. The method of FIG. 3 is similar to the method of FIG. The main difference is that the method according to FIG. 2 is based on a shared symmetric key 48, while the method according to FIG. 3 is based on an asymmetric key material.

Prior to establishing initial contact between the mobile device 12 and the device 14, both participants have asymmetric key material.

The mobile device 12 may receive the public key 104a and the corresponding private device key 102a and the public key 100 of the authentication entity from the public key infrastructure connection of, for example, a car manufacturer or other trusted service provider, .

The device 14 may receive the public key 104b and the corresponding private device key 102b and the public key 100 of the authentication entity from the public key infrastructure connection of, for example, the car manufacturer or other trusted service provider .

The device 14 acquires the key material at the time of production, and the mobile device 12 acquires the key material when uploading software or registering a service such as a car sharing service.

Upon establishing contact between the mobile device 12 and the device 14, a key exchange method 149 is performed, which may correspond to the key exchange method of FIG. As an example, a Diffie-Hellman method is shown. The mobile device 12 includes a private key 150a and a public key 152a and the device 14 includes a private key 150b and a public key 152b. Mobile device 12 and device 14 now exchange their public keys 152a and 152b.

In the key generation step 154, the mobile device 12 generates a shared key 156 from its private key 150a and the public key 152b of the device 14. Similarly, the device 14 generates the shared key 156 from its private key 150b and the public key 152a of the mobile device 12. Thus, the key exchange method 149 ends here.

Now, within the scope of signature generation 158, a first signature 160a is generated from the mobile device 12 via the shared key 156 to the private mobile device key 102a. Similarly, a second signature 160b is generated with the private device key 102b via the shared key 156 in the range of the signature generation 158 in the device 14. [

The first signature 160a and the signed public mobile device key 104a are then transmitted to the device 14 and the second signature 160b and the signed public device key 104b are transmitted to the mobile device 12, do. This is done through the same interface or connection that causes the key exchange method 149 to be performed. This may be, for example, a connection 44 with the interface or transmit / receive units 38 and 42 of FIG.

The device 14 is authenticated by encrypting the second signature 160b with the public device key 104b signed in the mobile device 12 and the public key 100 of the authentication entity. Similarly, in the context of the certificate 162, the mobile device 12 encrypts the first signature 160a with the public mobile device key 104a signed in the device 14 and the public key 100 of the authentication entity Authenticated.

Upon successful authentication 164, i.e., upon mutual authentication, contact establishment continues. For example, in the example of FIG. 1, another system, such as the bus 36 of the device 14 and / or another control device 34, is then activated by a control command of the control device 40.

Upon unsuccessful authentication 166, i. E., When at least one authentication 162 fails, the establishment of contact in device 14 or mobile device 12 is aborted.

Thus, the proposed method permits cryptographically secure connections through a method of pairing between participants who have not previously contacted each other, without having to have access to one of the participants of the two participants.

10 System 12 Mobile Device
14 vehicle 16 backend
18 authentication entities 20 data banks
22 Interface 24 Interface
26 Connection 28 Interface
30 Connections 32 Interface
34 Control unit 36 Bus system
38 transmitting / receiving unit 40 control device
42 Connecting the transmitting / receiving unit 44
46 Microprocessor 48 Symmetric key
49 Key exchange method 50a private key
50b private key 52a public key
52b Public Key 54 Key Generation
56 Shared Keys 58 Creating a signature
60a first signature 60b second signature
62 Authentication 64 Successful authentication
66 Failed Authentication
100 authentication entity's public key 102a private mobile device key
104a public mobile device key 102b private device key
104b public device key 150a private key
150b private key 152a public key
152b public key 154 key generation
156 Shared Keys 158 Creating a signature
160a first signature 160b second signature
162 Authentication 164 Successful authentication
166 Failed Authentication

Claims (11)

A method of providing security for an initial contact establishment of a mobile device (12) and a device (14), said device (14) being provided with a symmetric key (48) introduced via a trusted entity In this case,
- introducing the symmetric key (48) to the mobile device (12) via the trusted entity (16);
Performing a key exchange method (49) upon establishing contact with a result of the shared key (56) in the mobile device (12) and the device (14);
- generating a first signature (60a) from the mobile device (12) via the shared key (56) to the symmetric key (48);
- generating a second signature (60b) from the device (14) via the shared key (56) to the symmetric key (48);
- transmitting said first signature (60a) to said device (14) and said second signature (60b) to said mobile device (12);
- authenticating the device (14) by encrypting the second signature (60b) from the mobile device (12) to the symmetric key (48);
- authenticating the mobile device (12) by encrypting the first signature (60a) at the device (14) with the symmetric key (48); And
- the initial contact of the mobile device (12) and the device (14), including the step of continuing the contact establishment upon mutual successful authentication (164) or aborting the establishment of the contact (166) How to provide security for establishment. The method according to claim 1,
Characterized in that the symmetric key (48) is introduced into the device (14) at the time of production of the device (14). 3. The method according to claim 1 or 2,
Characterized in that the symmetric key (48) is introduced into the mobile device (12) prior to establishing the contact. The method of claim 3,
Characterized in that the keys are introduced into the mobile device (12) by the installation of a program. 5. The method according to any one of claims 1 to 4,
Characterized in that the key exchange method (49; 149) is based on a Diffie-Hellman method. ≪ Desc / Clms Page number 19 > 6. The method according to any one of claims 1 to 5,
Characterized in that confirmation is performed in the key exchange method by exchanging the signatures (60a, 60b; 160a, 160b). 7. The method according to any one of claims 1 to 6,
Characterized in that after the mutual authentication (64; 164) has been made, the other system (34, 36) required to perform the method in the device (14) A method of providing security for establishing an initial contact. A system for providing security for initial contact establishment of a mobile device (12) and a device (14)
Characterized in that the mobile device (12) and the device (14) are arranged to perform the method according to one of the claims 1 to 7. The mobile device (12) A system that provides security against. 9. The method of claim 8,
Wherein the device (14) is a vehicle and / or the mobile device (12) is a smartphone. 10. The method according to claim 8 or 9,
Characterized in that the mobile device (12) and the device (14) each comprise a transmitting / receiving unit (38, 42) for shared communication according to the Bluetooth low energy standard. A system that provides security against initial contact establishment. 11. The method according to any one of claims 8 to 10,
The apparatus (14) comprises a transmitting / receiving unit (38) installed to perform the method according to any one of claims 1 to 7 and a computer unit (40) connected thereto, Characterized in that the other system (34,36) of the device (14,16) can be activated via a control command of the computer unit (40) only after the authentication (64,164) A system that provides security against contact establishment.

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